Efficient batteries could use blood molecule

The next generation of batteries could function on a molecule that transports oxygen in blood and could also work in an environmentally friendly way.

These batteries have recently emerged and are called Lithium-oxygen (Li-O2) batteries. They could be a possible successor to lithium-ion batteries -the industry standard for consumer electronics- as they can function for a longer time period.

Once these batteries substitute the lithium-ion batteries electronic devices can run for weeks. For example electric cars could function four to five times longer than the current rate.

However, before this transition is made possible, scientists should find ways to make the Li-O2 batteries efficient for commercial use and stop the formation of lithium peroxide, a solid precipitate that coats the surface of the batteries’ oxygen electrodes. In order to make this possible a catalyst should be found which could efficiently aid a process known as oxygen evolution reaction, in which lithium oxide products decompose back into lithium ions and oxygen gas.

The Yale lab of Andre Taylor, associate producer of chemical and environmental engineering, has recognized the heme molecule as a better catalyst. The heme molecule was shown to improve the Li-O2 cell function by reducing the amount of energy needed to better the battery’s charge/discharge cycle times.

“When you breathe in air, the heme molecule absorbs oxygen from the air to your lungs and when you exhale, it transports carbon dioxide back out,” Taylor said. “So it has a good binding with oxygen, and we saw this as a way to enhance these promising lithium-air batteries.”

The lead author of the research Won-Hee Ryu a former postdoctoral researcher in Taylor’s lab said the the heme molecule makes up one of the two parts of hemoglobin, which is a carrier of blood in animal blood. Ryu also said in an Li-O2 battery, the molecule would lower the energy needed by the battery for the electrochemical reaction to take place.

The researchers said their discovery could help in the reduction amount of animal waste disposal.

“We’re using a biomolecule that traditionally is just wasted,” said Taylor. “In the animal products industry, they have to figure out some way to dispose of the blood. Here, we can take the heme molecules from these waste products and use it for renewable energy storage.”